The Caribbean Goes Geothermal
WHY YOU SHOULD CARE
Because Caribbean islands could help lead the way in weaning us from fossil fuels by tapping into heat energy deep within the Earth.
Forget the white-sand beaches and astonishing biodiversity. The Caribbean’s real treasure might be buried deep, deep underground, in the form of steam and piping-hot water — in other words, geothermal energy.
In recent years, the Antilles, lesser and greater, has emerged as a hub for geothermal energy exploration. Nevis and St. Vincent are soon to host private geothermal investment projects. The European Union recently awarded Dominica a $10.3 million grant to jump-start geothermal energy development. And on the eastern Caribbean island of Montserrat, geologists are using cutting-edge techniques to map the rocky subterranean surfaces below.
The stakes are high. If the region can harness the power of its heat — and it’s a big if — a nearly endless supply of energy could reward it. That, in turn, would free up billions of dollars Caribbean countries spend importing diesel, which fuels most of its power plants. Aruba, for instance, spends a staggering 16 percent of its GDP on diesel.
The Caribbean islands are ‘ideally positioned’ for geothermal energy development.
But tapping it is costly and risky, just like drilling for oil can be. Companies can spend millions of dollars on drilling a well only to find it empty. Small regional markets make it hard enough to attract the private investment needed to drill. Thus far, Guadeloupe is the only Caribbean island that uses geothermal energy for electricity. And although several wind farms and solar projects have sprung up on the breezy, sunny islands, geothermal projects have lagged behind, largely because of the financial risk.
That’s where the maps come in. Lessening the risk of drilling a well could lead to wider adoption of geothermal energy, and could spawn big opportunities besides. “The private sector won’t be so shy to put their money into projects in the early stages,” says Graham Ryan, a research fellow at the University of Auckland’s Institute of Earth Science and Engineering.
Geothermal energy is the intense heat deep within the Earth, seen in geysers, hot springs and volcanoes. It’s far more efficient than diesel-fueled power generation, and it doesn’t billow greenhouse gases into the air, either. Unlike wind or solar power, which depend on weather conditions, geothermal energy is always available. The Earth continuously generates roughly 44 terawatts, or trillions of watts, of heat — three times the global population’s current energy use.
One technique that Ryan and his colleagues have used, called magnetotellurics, relies on what’s essentially a giant metal detector to find molten magma, while seismic tomography uses the pressure waves created by carefully detonated explosions to generate images of rocks underground.
The Caribbean Islands are “ideally positioned” for geothermal energy development, says Bruce Cutright, chief technology officer at Nevis Renewable Energy International. They perch on two continental plate boundaries, where slabs of the Earth’s crust grind slowly past each other, and hot molten magma flows upward, warming the surrounding rocks to create a heat reservoir. Seawater seeps through crevices and pores in the magma-baked rocks. This hot water then flows toward the surface and can be extracted by drilling geothermal wells. Steam from the rising, boiling liquid rorates power-plant turbines to generate electricity.
And the region is in dire need of cheap energy. Countries often spend 15 percent or more of their total GDP on electricity, impeding development and perpetuating poverty. Only a few Caribbean countries have natural gas reserves, which makes the region heavily dependent on imported diesel — whose prices saw a threefold spike over the past decade. Blackouts and brownouts are normal.
To boost the likelihood of drilling a productive geothermal well, Ryan and other University of Auckland researchers have employed an array of techniques to create a map of the rocks below the surface of Montserrat in the eastern Caribbean. Last year, the Iceland Drilling Co. drilled Montserrat’s first two geothermal wells, which preliminary tests suggest could generate more power than the population needs.
“It’s formalizing how you put together different kinds of information … and trying to see those all fit together in three dimensions and creating an interpretation of the geothermal system,” Ryan says.
Several companies are planning projects on Nevis, St. Vincent and other islands.
But Ryan notes that geothermal energy “is not going to solve the whole of the world’s energy problems.” For one, not all regions have high geothermal potential. There are safety concerns, too: Hot water from geothermal sources can harbor trace amounts of toxic chemicals like mercury and arsenic, which evaporate into the air as the water cools.
Today, geothermal plants can be found in roughly 25 countries. Now researchers are looking at island nations, where the ocean can channel the heat energy to shallower depths. Indonesia and the Philippines already rely on geothermal electricity. Researchers are also investigating the Northern Mariana Islands’ geothermal energy potential.
A predominantly geothermal energy-powered Caribbean might still be some years away. But the future “is very bright,” said Gunnar Örn Gunnarsson, chief operating officer at Reykjavik Geothermal. There’s “a high probability that a good portion of all energy needs on the islands could come from geothermal resources.” Which means these laid-back islands could lead the way to a fossil-fuel-free future.